Fluid control system

ABSTRACT

A fluid control system for dishwashers, clothes washers, and the like. A series type fill valve has a hydraulic actuator located between the two valve operators and controlling a drain valve through a mechanical linkage. A flow control device at the inlet to the first valve maintains the pressure at the actuator at a level too low for activation during a fill cycle when both solenoid operated valves are open. Draining is effected by opening of the first valve only, which pressurizes the linear actuator to open the drain valve. Means are provided for bleeding off pressure at the actuator when both solenoid operated valves are closed to prevent inadvertent opening of the drain valve.

United States Patent [151 3,704,721

Schmitz et al. 1 Dec. 5, 1972 s41 FLUID CONTROL SYSTEM 2,744,719 5/1956McRae ..2s1/2s x [72] Inventors: Ambrose L schmitz Hoffman 2,910,26610/1959 COndellO et a1. ....2s1/305 x Estates; William McCarty"3,396,848 8/1968 Kozel ..25l/30 X Skokie; Howard L. Erickson, Ben-Senvine, n f m jrzmary Ex fa mmerzR lobggt G. Nilson ttorne ea no 0 [73]Assignee: Eaton Corporation, Cleveland, Ohio y g y 221 Filed: Oct. 1,1970 7] ABSTRACT [21] A L N 77,157 A fluid control system fordishwashers, clothes washers, and the like. A series type fill valve hasa hydraulic actuator located between the two valve [52] U.S. Cl...137/l02, l37/596.l6, 251/30, operators and controlling a drain valvethrough a I 5] I t Cl 251/305 mechanical linkage. A flow control deviceat the inlet d 4 to the first valve maintains the pressure at theactuator 0 care 251225 at a level too low for activation during a fillcycle when both solenoid operated valves are open. Draining is effectedby opening of the first valve only, which [56] References C'tedpressurizes the linear actuator to open the drain valve. UNITED STATESPATENTS Means are providedfor hleeding off pressure at the actuator whenboth solenoid operated valves are s i closed to prevent inadvertentopening of the drain U ivan t valve 3,568,975 3/1971 Obermaier......251/306X 1,643,753 9/1927 Slattery ..25l/306 X 10 Claims, 3 DrawingFigures PATENTEDBEB 1 1 3.704.721

SHEET 1 0F 2 INVENTORS 72'46/1/0 & faam A'rromm V5 PATENTED DEC 5 I97? 3704 721 SHEET 2 [IF 2 INVENTORS ZZAG/l/O & 7000/ flrmPA/H s FLUIDCONTROL SYSTEM This invention relates to a fluid control system and moreparticularly to a combination fill and drain valve for an automaticdishwasher or the like.

Automatic appliances such as dishwashers, clothes washers, and the likerequire valves for filling and draining which operate automaticallyaccording to a time sequence. Ordinarily, such fill and drain valves areseparate and distinct units, each requiring a valve element and asolenoid to actuate the valve element. In order to provide maximumprotection against flooding of the room in which the washer is operated,it is desirable to provide an additional solenoid actuated fill valve inseries with the first so that malfunction of one of the valves will notprevent automatic shut-off of the water supply.

From the standpoint of both cost and space, it would be most desirableto combine the functions of the above valves into a single integratedunit without sacrificing performance or safety.

Accordingly, it isan object of the present invention to provide'a fluidcontrol system for a dishwasher or the like in which the fill and drainvalves are combined into a single assembly. 7 7

Another object of the invention is to provide such a system whichretains the safety features of a dual fill valve, that is, one in whichtwo independent solenoid valve elements must be opened in order toeffect filling of the machine.

Another object of the invention is to provide such a combination valveassembly employing only two solenoid elements.

Another object of the invention is to provide such a combination inwhich the drain valve element, in particular, provides complete shut-offin the closed position and substantially unrestricted flow in the openposition.

Another object of the invention is to provide such a combination valvein which operating power requirements are minimized.

Another object of the invention is the provision of such a valve whichis essentially noiseless in operation.

To meet the above objectives, the present invention provides a fluidcontrol system comprising two solenoid-actuated fill valve elements inseries having a pressure tap between them in communication with apressure-operated linear actuator. The actuator controls the opening andclosing of a butterfly-type drain valve.

To fill the washtub, both series elements must be opened. Opening of thefirst valve element only pressurizes the actuator to open the drainvalve. When both valve elements are open, a flow control at the inlet tothe first element reduces the pressure to the actuator to a levelinsufficient to operate it, thus obviating opening of the drain valveduring a fill cycle. Means are also provided to prevent a pressurebuildup at the pressure tap when both valve elements are closed toprevent inadvertent opening of the drain valve.

The above arrangement is particularly adaptable to the use of a drainvalve of the butterfly type which has the advantages of noiselessoperation, straight-through flow capability, and which can be designedto blow closed" to provide positive sealing.

Other objects and advantages will be apparent from the specificationwhen taken in connection with the accompanying drawings, wherein:

FIG. 1 is a fragmentary front elevation of a washing apparatusincorporating the fluid control system of the invention;

FIG. 2 is an enlarged transverse sectional view of the fill and drainvalve; and I FIG. 3 is an enlarged transverse sectional view of analternative embodiment of the invention.

Referring to the drawings, in FIG. 1 there is illustrated a dishwasher,designated generally by the numeral 11, comprising a supporting cabinet12, a washtub 13, motor 14, drain pump and a combination fill and drainvalve assembly 16. Hot water is delivered to the tub 13 by a supply line17 connected to the fill inlet 18 of valve assembly 16, and a hose l9connecting the tub with the fill outlet 20 of the valve. A drain hose 21connects the drain outlet 22 of the pump 15 to the drain inlet 25 ofvalve assembly 16, and a hose 23 connects the drain outlet 24 to thehousehold sewer system.

Referring to FIG. 2, the combination fill and drain valve 16comprisesfirst and second solenoid operated valve elements 30 and 31within an integral housing 32, a pressure operated linear actuator 33communicating with a chamber 34 constituting a pressure tap between thetwo valve elements, and a butterfly valve 35 actuated by the linearactuator.

The inlet 18 to the first valve element 30 includes a filter screen 36and a flow control washer 37, the flow control washer being of awell-known type which contracts under pressure in order to maintain asubstantially constant downstream pressure under varying inlet pressureconditions.

The first solenoid valve element 30 communicates with the downstreamside of the flow control washer by means of a passage 38 formed in thevalve body 32 and is illustrated herein as being of the pilot operateddiaphragm type. The valve essentially comprises a diaphragm 39, a pilotvalve seat member 40 operatively attached to the diaphragm, a pilotvalve element 41 operable to open and close a pilot orifice 42 in theseat member 50, and a core member 43, which carries the pilot valve 41.The core member and valve are held in a normally closed position by aspring 44 and is moved upward to open the pilot orifice by means of asolenoid 45. Opening of the pilot valvecauses the diaphragm to move offa seat 46 formed in the valve body to open the main valve outlet passage47.

The outlet passage 47 of the first valve element 30 opens into thechamber or pressure tap 34 of the linear actuator 33. The actuator 33,illustrated in its energized position in FIG. 2, comprises a housing 51bolted or otherwise fastened to the valve body 32, a rolling diaphragm52 clamped between the housing and the valve body, a piston 53 throughwhich movement of the diaphragm is transferred, and a spring 54 actingbetween the housing 51 and the piston. The spring normally biases thediaphragm upward in its de-energized position as indicated in full linein FIG. 3 and by the broken lines in FIG. 2. An actuating rod 55is'connected to the piston 53 and depends downward therefrom through anopening in the housing 51 and ends adjacent the body 56 of butterflyvalve 351 The end of rod 55 is pivotally attached to a crank arm 57which actuates the butterfly element 58 of the valve.

The butterfly valve comprises the bo dy 56, including inlet connectionand outlet connection 24 and, the butterfly element 58. The butterflyelement 58 comprises a metallic insert 59 and a resilient sealingelement 60 molded to the insert. One end 61 of the crank arm 57 extendsthrough the valve body 56 perpendicular to the direction of flow and iswelded or otherwise fastened to the metallic insert 59.

A deflector or baffle 62 formed in the inlet side of the valve body 56deflects all flow below the end 61 of the crank arm and prevents wastematerial from wrapping around the butterfly element. The butterflyelement 58 is slightly overbalanced in the blow closed position to allowdrain pump pressure to aid in keeping the valve closed during a wash orrinse cycle. The drain pump runs continuously during all dishwashercycles except drying.

When the chamber 34 above the rolling diaphragm 52 is pressurized, thediaphragm moves downward from the broken line to the solid line positionof FIG. 2 forcing the piston and attached rod downward to move thebutterfly valve from a closed (broken line) position to an open (fullline) position Valve 31 is'a solenoid valve similar to the valve elementand need not be described in detail. Suffice it to say that energizingthe solenoid 65 of valve 31 operates to open the valve to transfer fluidfrom the outlet passage 47 of valve 30 to the inlet passage of valveelement 31, (through chamber 34) and then outward through the filloutlet 20 to the fill hose 19.

To operate the valve 16 in the till mode of a typical washer cycle, bothsolenoids 45 and 65 are energized, placing fill valve elements 30 and 31in their open positions to establish a flow path from the inlet 18,through valve element 30, chamber 34, and valve element 31 to thefill'hose 19. The flow control washer 37 at the inlet of valve 30 isdesigned to provide a predetermined pressure drop across valve 16 underflow. conditions, for example, 2 psi. The linear actuator 33, however,is designed to operate at a higher pressure, for example, 6-12 psi, suchthat when flow is established through valves 30 and 31, the spring 54maintains the actuator 33 in its de-energized position. Thus the drainvalve remains closed during this portion of the cycle.

At the end of a fill cycle, the valve elements 30 and 31 are operated ina prescribed manner in order to prevent a pressure build-up in chamber34 which could cause premature opening of the drain valve 35. This canbe accomplished either by employing a slow-closing valve as valveelement 31, allowing time for the pressure in chamber 34 to bleed off,or the cycle can be set up such that the valve element 31 always closesafter valve element 30 to provide the required bleed-off of pressure inchamber 34. An alternative method, illustrated in FIG. 3, is to includea bleed port 66 between chamber 34 and the outlet ,of valve element 31.This bleeds unwanted pressure into the machine, but has the disadvantageof allowing a small amount of fill water to enter the tub during thedrain cycle. To better illustrate the action of the drain-valve 35, thelinear actuator 33 is shown in its de-energized position in FIG. 3.

OPERATION Referring to FIGS. 1 and 2, consider a typicaldishwashercycle. As the dishwasher starts, the drain valve 33 is openedmomentarily to discharge residual water that may have accumulated in thetub. To initiate drain valve opening, the solenoid coil 45 of valveelement 30 is energized to open the valve allowing water to flow intochamber 34. As the chamber fills, water pressure acting on rollingdiaphragm 52 forces the actuator piston 53 and its associated actuatingrod 55 downward, rotating the butterfly element 58 clockwise, as shown,to open the drain valve. In order to prevent high pressure forces frombeing transmitted to the butterfly assembly, the piston 53 is designedto bottom out against the housing 51 just as the butterfly valvereachesits full open position.

To convert from adraining mode to a filling mode, the solenoid coil 65of valve 31 is energized to open the valve. Both fill valves are nowopen. As flow is established through the valves 30 and 31, theflowcontrol washer 37 creates a pressure drop upstream of the actuator 33,insuringthat the pressure in chamber 34 is maintained at a level too lowto overcome the force of spring 54. As a result, the spring returns thebutterfly valve to its closed position. s I I After the required timedtill, both coils 45 and 65 are de-energized and the'fill valves shutoff. T o insure that a pressure buildup will not occur in the chamber34, the timer can be set up to close valve element 30 a fraction of asecond before element 31. 7

When the rinse or wash cycle is completed the drain valve 35 is openedagain as discussed above. After the final drain of a complete washcycle, the drain valve 35 must be closed to prevent back-flow from thedrain into the dishwasher during the drying cycle. This can beaccomplished by setting the timer to momentarily open valve element 31to relieve pressure in chamber 34 and close the drain valve.

We now claim:

1. A fluid control system comprising fluid receiving means, an inletpassage for conducting fluid under pressure from a source to saidreceiving means, a discharge passage for conducting the fluid from saidreceiving means, first valve means operable to close said inlet passage,second valve means operable to close said inlet passage locateddownstream of the first, pressure control means operable to cause apressure drop between said valves when both of said valves are open, andmeans responsive to fluid pressure in said inlet passage between saidvalve means for opening said discharge passage when said first valveonly is open.

2. A fluid control system as claimed in claim 1, in which said pressurecontrol means comprises flow restrictor means upstream of said firstvalve means.

3. A fluid control system as claimed in claim 1, in which said meansresponsive to fluid pressure comprises a pressure-operated linearactuator, and a valve in said discharge passage operatively connected toan output member of said actuator.

4. A fluid control system as claimed in claim 3, in which said valvecomprisesa body having seating surfaces formed on the inside wallthereof, a butterfly element pivotally supported within said body, saidbutterfly element having resilient sealingsurfaces formed thereonengageable with said seating surfaces, and a crank arm connecting saidbutterfly element to the output member of said linear actuator.

5. A fluid control system as claimed in Claim 4, including baffle meansformed within said body and operable to force dis-charged fluid betweenthe inside wall of said body and one lobe of said butterfly element.

6. A'valve assembly comprising a first valve element, a second valveelement in series with a first, a flow control washer operable to causea pressure drop between said valve elements when both are open andsubject to fluid flow, a pressure tap between said valve elements, athird valve element independent of said first and second elements, andpressure responsive means communicating with said pressure tap andoperable to open said third valve element when said first valve only isopen and to close said third valve element when both said first andsecond valve elements are open.

7. A valve assembly as claimed in claim 6, in which said meansresponsive to fluid pressure comprises means defining a pressure tightchamber communicating with said pressure tap, a rolling diaphragmclosing one end of said chamber, an actuating rod operatively connectedto said rolling diaphragm for linear movement thereby, and means biasingsaid rolling diaphragm in a direction tending to reduce the volume ofsaid chamber, whereby a predetermined pressure at said pressure tap willmove said diaphragm against said biasing means.

8. A valve assembly as claimed in Claim 6, in which said third valveelement comprises a body portion having inlet and outlet connections,sealing surfaces formed within said body portion, a butterfly elementpivotally supported for rotation about a transverse axis of said body,resilient sealing surfaces formed on said butterfly element engageablewith said seating surfaces, and a crank arm disposed outside said bodyand operable to rotate said butterfly element from a closed positionwith said sealing surfaces in contact with said seating surfaces to anopen position with said surfaces out of contact. I

9. A valve assembly as claimed in Claim 8, in which said butterflyelement is overbalanced in a direction tending to force it into itsclosed position when subjected to fluid pressure from the inlet side ofsaid valve.

10. A valve assembly comprising a first valve element; a second valveelement in series with the first; pressure control means operable tocause a pressure drop between said valve elements when both are open andsubject to fluid flow; a pressure tap between said valve elements; athird valve element independent of said first and second element andhaving a body portion including inlet and outlet connections, sealingsurfaces form within said body portion, a butterfly element pivotallysup-ported for rotation about the transverse axis of said body,resilient sealing surfaces formed on said butterfly element engageablewith said sealing surfaces, and a crank arm disposed outside said bodyand operable to rotate said butterfly element from a closed positionwith said sealing surfaces in contact with said seating surfaces to anopen position with said surfaces out of contact, and said body portionhaving baffle means within said body operable to confine the flow offluid therethrough to an area between one wall of said body and saidtransverse axis, and pressure responsive means communicating with saidpressure tap and operable to open said third valve element when saidfirst valve only is open and to close said third valve element when bothsaid first and second valve elements are open.

1. A fluid control system comprising fluid receiving means, an inletpassage for conducting fluid under pressure from a source to saidreceiving means, a discharge passage for conducting the fluid from saidreceiving means, first valve means operable to close said inlet passage,second valve means operable to close said inlet passage locateddownstream of the first, pressure control means operable to cause apressure drop between said valves when both of said valves are open, andmeans responsive to fluid pressure in said inlet passage between saidvalve means for opening said discharge passage when said first valveonly is open.
 2. A fluid control system as claimed in claim 1, in whichsaid pressure control means comprises flow restrictor means upstream ofsaid first valve means.
 3. A fluid control system as claimed in claim 1,in which said means responsive to fluid pressure comprises apressure-operated linear actuator, and a valve in said discharge passageoperatively connected to an output member of said actuator.
 4. A fluidcontrol system as claimed in claim 3, in which said valve comprises abody having seating surfaces formed on the inside wall thereof, abutterfly element pivotally supported within said body, said butterflyelement having resilient sealing surfaces formed thereon engageable withsaid seating surfaces, and a crank arm connecting said butterfly elementto the output member of said linear actuator.
 5. A fluid control systemas claimed in Claim 4, including baffle means formed within said bodyand operable to force dis-charged fluid between the inside wall of saidbody and one lobe of said butterfly element.
 6. A valve assemblycomprising a first valve element, a second valve element in series witha first, a flow control washer operable to cause a pressure drop betweensaid valve elements when both are open and subject to fluid flow, apressure tap between said valve elements, a third valve elementindependent of said first and second elements, and pressure responsivemeans communicating with said pressure tap and operable to open saidthird valve element when said first valve only is open and to close saidthird valve element when both said first and second valve elements areopen.
 7. A valve assembly as claimed in claim 6, in which said meansresponsive to fluid pressure comprises means defining a pressure tightchamber communicating with said pressure tap, a rolling diaphragmclosing one end of said chamber, an actuating rod operatively connectedto said rolling diaphragm for linear movement thereby, and means biasingsaid rolling diaphragm in a direction tending to reduce the volume ofsaid chamber, whereby a predetermined pressure at said pressure tap willmove said diaphragm against said biasing means.
 8. A valve assembly asclaimed in Claim 6, in which said third valve element comprises a bodyportIon having inlet and outlet connections, sealing surfaces formedwithin said body portion, a butterfly element pivotally supported forrotation about a transverse axis of said body, resilient sealingsurfaces formed on said butterfly element engageable with said seatingsurfaces, and a crank arm disposed outside said body and operable torotate said butterfly element from a closed position with said sealingsurfaces in contact with said seating surfaces to an open position withsaid surfaces out of contact.
 9. A valve assembly as claimed in Claim 8,in which said butterfly element is overbalanced in a direction tendingto force it into its closed position when subjected to fluid pressurefrom the inlet side of said valve.
 10. A valve assembly comprising afirst valve element; a second valve element in series with the first;pressure control means operable to cause a pressure drop between saidvalve elements when both are open and subject to fluid flow; a pressuretap between said valve elements; a third valve element independent ofsaid first and second element and having a body portion including inletand outlet connections, sealing surfaces form within said body portion,a butterfly element pivotally sup-ported for rotation about thetransverse axis of said body, resilient sealing surfaces formed on saidbutterfly element engageable with said sealing surfaces, and a crank armdisposed outside said body and operable to rotate said butterfly elementfrom a closed position with said sealing surfaces in contact with saidseating surfaces to an open position with said surfaces out of contact,and said body portion having baffle means within said body operable toconfine the flow of fluid therethrough to an area between one wall ofsaid body and said transverse axis, and pressure responsive meanscommunicating with said pressure tap and operable to open said thirdvalve element when said first valve only is open and to close said thirdvalve element when both said first and second valve elements are open.